Vehicle, vehicle system and method for increasing safety and/or comfort during autonomous driving

ABSTRACT

A vehicle, vehicle system and method for increasing at least one of safety and comfort during autonomous driving is provided. The vehicle system includes an autonomous drive arrangement with multiple sensors, and a vehicle control arrangement. The vehicle system is configured to determine an estimated probability that at least one sensor will become unavailable, or an estimated time/distance ahead until at least one sensor is determined to become unavailable. The vehicle system is further configured to activate at least one countermeasure based on at least one of the estimated probability, the estimated time and the estimated distance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority benefits under 35 U.S.C.§119(a)-(d) to European Patent Application No. EP 14160567.5, filed Mar.18, 2014, which is incorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments herein relate to a vehicle system arranged to increasesafety and/or comfort during autonomous driving. Embodiments hereinfurther relate to a vehicle comprising a vehicle system arranged toincrease safety and/or comfort during autonomous driving, and to amethod for increasing safety and/or comfort during autonomous driving.

BACKGROUND

Some modern vehicles are equipped with one or more systems which allowthe vehicle to be arranged into a semi-autonomous and/or autonomousdrive mode. Such systems may include predictive safety systems, adaptivecruise control systems, lane-departure warning systems, navigationsystems, communication systems and/or automatic brake control systems.Some of the systems may monitor the vehicle surroundings in order tocontrol a host vehicle position relative a road on which the hostvehicle drives, and may further determine positions and/or velocities ofsurrounding objects, such as other vehicles, pedestrians and variousobstacles. Such systems may calculate whether a collision between thehost vehicle and other vehicles or objects is imminent, and may in suchcase calculate an alternative route, and/or warn a driver of the hostvehicle.

In order to collect information regarding the host vehicle surrounding,the host vehicle is generally equipped with various sensors that monitorthe host vehicle surrounding. Such sensors may include one or morecameras, radar-units and/or lidar-units.

In addition to the sensors, a communication system in the host vehiclemay be arranged to communicate with one or more external communicationarrangements, such as remote servers/clouds, other vehicles and/orroadside units. The host vehicle may receive information on e.g.available routes, obstacles and traffic information via thecommunication arrangement.

In order to provide autonomous drive functions, the host vehicle orsystems thereof depends on the information received through the sensorsand/or the communication arrangement. If one or more of the sensorsbecome unavailable, or if the communication between the host vehicle andexternal communication arrangements is interrupted, some or allautonomous drive functions may be disabled. A driver may then need tooperate the vehicle, or some vehicle functions, manually.

If a sensor or communication-link becomes unavailable, the autonomousvehicle may be configured to stop. In some cases the driver may have tooperate the vehicle manually with short notice. Both unplanned stops ofthe autonomous vehicle and a short preparation time for manual drivingmay be annoying and/or stressful for the driver.

Improvements related safety and/or comfort during autonomous driving aretherefore desirable.

SUMMARY

Embodiments herein aim to provide a vehicle system arranged to increaseat least one of safety and comfort during autonomous driving of a hostvehicle, eliminating or at least reducing the problems and/or drawbacksassociated with prior art systems.

According to an embodiment, this is provided by a vehicle systemarranged to increase at least one of safety and comfort duringautonomous driving of a host vehicle, the vehicle system comprising anautonomous drive arrangement that comprises; a plurality of sensorsarranged to monitor at least one of a vehicle surrounding and a vehiclecommunication system status, a processing unit and a controlarrangement, arranged to control steering and velocity of the hostvehicle based on information received from the sensors, wherein thevehicle system is arranged to determine, by the processing unit, atleast one of an estimated probability that at least one sensor willbecome unavailable, and an estimated time or distance ahead until atleast one sensor is determined to become unavailable. The determinationis based on a, by at least one of the sensors, detected host vehicle orhost vehicle surrounding condition. The vehicle system is furtherarranged to activate, by the autonomous drive arrangement, at least onefirst countermeasure based on at least one of the estimated probability,the estimated time and the estimated distance.

Since the vehicle system is arranged to determine at least one of theestimated probability that at least one sensor will become unavailable,the estimated time and/or the estimated distance ahead until at leastone sensor is determined to become unavailable, and further is arrangedto activate at least one first countermeasure based on at least one ofthe estimated probability, the estimated time and the estimateddistance, both safety and comfort are increased.

A sensor may be considered to be unavailable if the performance of thesensor is below a threshold level. When the sensor performance is belowthe threshold level, input from the sensor may not be robust and/oraccurate to such an extent that the sensor input may be used for theautonomous drive functions.

The vehicle system may be configured to, very quickly, determineupcoming sensor unavailability. If, for example, an oncoming vehicledrives in a puddle, water may splash up against the host vehicle.Sensors in/on the host vehicle may then be blocked by the water. Whenthe sensors detect that water splash is approaching the host vehicle,the vehicle system may determine that one or more of the sensors willbecome unavailable for a short while, e.g. until the water has, at leastpartly, disappeared from the one or more sensors. If the oncomingvehicle drives near an intended/expected host vehicle travellingtrajectory and there are puddles on the road between the oncomingvehicle and the host vehicle, the vehicle system may estimate theprobability that one or more sensors become unavailable to be high, suchas 50-100%. Similarly, if puddles on the road are large or if the roadcomprises many puddles, the vehicle system may determine that it islikely that one or more sensors will become unavailable.

The vehicle system may further determine the estimated distance until atleast one sensor will become unavailable. If one or more sensor detectsa large puddle 50 meters ahead of the host vehicle, it may determinethat the estimated probability for sensor unavailability e.g. 50-60meters ahead is high.

The vehicle system may further determine the estimated time until atleast one sensor will become unavailable. If one or more sensor detectsa large puddle 50 meters ahead of the host vehicle, it may determinethat the estimated probability for sensor unavailability e.g. 50-60meters ahead is high. The host vehicle system may further receiveinformation of the host vehicle velocity, e.g. via a sensor, or viacommunication with other vehicle systems. If the vehicle system compriseinformation e.g. on a current host vehicle velocity of 25 m/s, it maydetermine that it is likely that sensor unavailability may occur inapproximately 2 seconds.

If the vehicle system determines that it is probable that a sensor soonwill become unavailable one or more functional countermeasures areactivated. Hereby, a vehicle operator will not be forced to take controlof the vehicle due to sensor unavailability, which may imply disablementof some or all autonomous drive functions.

For example, if the vehicle system determines that it is probable that asensor soon will become unavailable due to water splash from surroundingvehicles, the vehicle system may instead rely on sensor information fromsensors which is less likely to be affected from the water splash.Alternatively or in addition, the driver may be alerted that he/shepossibly needs to operate the host vehicle manually during the time theone or more sensors are unavailable.

Thus, due to the determination of upcoming sensor unavailability thevehicle operator may be alerted before the control arrangement isaffected of the reduced sensor input, such that he/she may control someor all drive functions manually, or other sensors may compensate for theunavailable sensor. In addition, other drive and/or safety systems maybe activated as a countermeasure to the determined sensorunavailability.

Thus, hereby is provided a vehicle system which is arranged to increaseat least one of safety and comfort during autonomous driving,eliminating or at least reducing the problems and/or drawbacksassociated with prior art solutions.

According to some embodiments a sensor is determined to be unavailableif a sensor performance level is below a threshold sensor performancelevel, and in that at least one first countermeasure is activated onlyif the sensor is determined to be unavailable for a duration of timethat exceeds a threshold duration of time.

Since the sensor is determined to be unavailable if a sensor performancelevel is below a threshold sensor performance level, and since at leastone first countermeasure is activated only if the sensor is determinedto be unavailable for a duration of time that exceeds a thresholdduration of time, the vehicle system is arranged to provide autonomousdrive functions for shorter periods of sensor unavailability.

A threshold duration of time may be dependent on factors such as thevehicle speed, road type, traffic intensity around the host vehicle etc.During the sensor unavailability the control arrangement may be arrangedto control steering and velocity of the host vehicle based on deadreckoning, i.e. by sensor data gathered just before the sensorunavailability. In some cases some sensor data may be used also when thesensor performance is degraded.

In the example given above, where some sensors were determined to becameunavailable due to water splash from a puddle, the processing unit maydetermine that sensor unavailability will occur for 1,5 seconds. If athreshold duration of time is e.g. 3 seconds, the countermeasure(s) willnot be activated. If the threshold duration of time is e.g. 1 second, atleast one countermeasure will be activated.

According to some embodiments the autonomous drive arrangement isarranged to activate at least one second countermeasure based on atleast one of the estimated probability, the estimated time and theestimated distance.

Since the autonomous drive arrangement is arranged to activate at leasttwo different countermeasures, safety and comfort may be enhanced. Forexample, a safety distance to surrounding vehicles may be increased andthe vehicle operator may be alerted of an increased possibility thathe/she may need to operate the host vehicle manually soon.

According to some embodiments the activation of at least onecountermeasure is based on a, by at least one of the sensors, detectedhost vehicle surrounding condition in form of sunlight, negativelyaffecting a vehicle camera sensor.

Since at least one countermeasure is activated when it is determinedthat sun-light will negatively affect a vehicle camera sensor, thecountermeasure is activated before sunshine hits e.g. a camera lens andsaturate the camera sensor. Due to this activation the vehicle operatormay be alerted in advance in situations when it is likely that a sensorfunctionality will decrease because of sunlight.

According to some embodiments, the vehicle system is arranged toactivate, by the autonomous drive arrangement, at least one firstcountermeasure if the estimated probability that at least one sensorwill become unavailable exceeds a threshold probability or if theestimated time or distance ahead until at least one sensor is determinedto become unavailable is below a threshold level.

Since the vehicle system is arranged to activate at least one firstcountermeasure if the estimated probability that at least one sensorwill become unavailable exceeds a threshold probability or if theestimated time or distance ahead until at least one sensor is determinedto become unavailable is below a threshold level, the vehicle system iscapable to deal with several possible scenarios. If it is determinedthat the probability for sensor unavailability exceeds a predeterminedthreshold value, a countermeasure is activated. The thresholdprobability may be a calculated value, above which the likelihood forpossible dangerous scenarios is increased. The threshold probability maybe input into the vehicle system in advance.

Alternatively, or in addition to, the estimated probability that atleast one sensor will become unavailable, one or more countermeasuresmay be activated if the estimated time or distance ahead, until at leastone sensor is determined to become unavailable, is below a thresholdlevel. As mentioned above, when a sensor is determined to becomeunavailable, also the time and/or distance is calculated for when/wherethe sensor temporarily will terminate to function properly. If theamount of time/distance until the determined sensor unavailability isless than a threshold limit, at least one countermeasure is activated.The threshold limit may be indicative of a number of milliseconds,seconds or meters.

According to some embodiments the activation of at least onecountermeasure is based on a, by at least one of the sensors, detectedhost vehicle surrounding condition in form of a weather condition,negatively affecting at least one of a camera sensor, a radar sensor anda lidar sensor.

Since the activation of at least one countermeasure is based on aweather condition, negatively affecting at least one of a camera sensor,a radar sensor and a lidar sensor, a countermeasure can be activatede.g. when heavy rain, snow or fog is expected to decrease a sensorcapacity. For example, humidity may affect a camera sensor, snow mayaffect a radar-sensor and ice-crystals in the air may affect alidar-sensor.

According to some embodiments the vehicle system further comprises acommunication system arranged for communication between the host vehicleand external communication arrangements, and that the host vehicle isarranged to receive data relating to host vehicle surrounding conditionsfrom the external communication arrangements.

Since the host vehicle is arranged to receive data relating to hostvehicle surrounding conditions from external communication arrangements,systems and/or persons in the host vehicle may be informed of upcomingsituations wherein sensor capacity may be limited. The situations may berelated to map information, road geometry/inclination/sloping, and/orobstacles such as buildings, crests and trees in the vicinity of theroad. The host vehicle surrounding conditions received by the hostvehicle may also relate to e.g. a sun position, possibly expressed as amathematical formula. External communication arrangements may becommunication arrangements in other vehicles, roadside units or otherroadside infrastructure with communication capacity, remote servers/“thecloud”.

According to some embodiments the activation of at least onecountermeasure is based on a, by at least one of the sensors, detecteddecreased communication capacity between the host vehicle and at leastone external communication arrangement.

Since the activation of at least one countermeasure is based on adetected decreased communication capacity between the host vehicle andat least one external communication arrangement, the vehicle system maye.g. alert a vehicle operator of the decreased communication capacity.For example, if a GPS-signal is blocked when the host vehicle enters atunnel, some autonomous drive functions may be disabled. The vehiclesystem may then indicate to the vehicle operator that he/she needs tooperate the vehicle manually through the tunnel.

According to some embodiments the activation of at least onecountermeasure is based on a host vehicle surrounding conditioninformation indicative of a communication capacity in a predefinedgeographical area.

Since the activation of at least one countermeasure is based on a hostvehicle surrounding condition information indicative of a communicationcapacity in a predefined geographical area the vehicle system may e.g.alert a vehicle operator. For example, if a communication capacity in anupcoming area is reduced, some autonomous drive functions may bedisabled. The vehicle system may then indicate to the vehicle operatorthat he/she needs to operate the vehicle manually through that area. Thecommunication capacity may be detected by a sensor or sent to the hostvehicle. The information may relate to any kind of communicationcapacity, such as radio-signals, electrical signals and/orelectromagnetic wave signals. A communication capacity may decrease e.g.due to package loss and/or decreased signal strength. The decreasedcommunication capacity in the geographical area may relate to e.g. theterrain, the distance to external communication arrangements and/or thenumber of vehicles in the area.

According to some embodiments the vehicle system is arranged to activateone or more countermeasure selected from the group of: a host vehicleoperator alert, indicative of an upcoming reduced autonomous drivingcapacity, a disablement of one or more autonomous drive functions, anincrease safety distance to at least one object in the vehiclesurrounding, a change of vehicle velocity, activation of dead reckoningand a stop of the vehicle.

Since the vehicle system is arranged to activate one or morecountermeasure selected from the group of: a host vehicle operatoralert, indicative of an upcoming reduced autonomous driving capacity, adisablement of one or more autonomous drive functions, an increasesafety distance to at least one object in the vehicle surrounding, achange of vehicle velocity, activation of dead reckoning and a stop ofthe vehicle both safety and comfort are enhanced.

The at least one first countermeasure may be selected based on factorssuch as the vehicle speed, road type, traffic intensity around the hostvehicle etc. If sensor unavailability is determined to occur within arelatively short time or distance, a vehicle operator may be alerted. Ina traffic situation with other vehicles near the host vehicle, a firstcountermeasure may be to increase a safety distance to one or more ofthe surrounding vehicles. A first countermeasure may also be to increasea safety distance to other objects in the vehicle surrounding, such asroad users, pedestrians etc. The at least one first countermeasure mayalso be selected based on the type of sensor which is determined tobecome unavailable.

Thus, hereby is provided a vehicle system, eliminating or at leastreducing the problems and/or drawbacks associated with prior artsystems.

Embodiments herein also aim to provide a vehicle comprising a vehiclesystem arranged to increase at least one of safety and comfort duringautonomous driving of a host vehicle, without the problems or drawbacksdescribed above.

According to some embodiments, this is provided by a vehicle, whereinthe vehicle comprises a vehicle system according to embodiments herein.

Thus, hereby is provided a vehicle, eliminating or at least reducing theproblems and/or drawbacks associated with prior art vehicles.

Embodiments herein also aim to provide a method for increasing at leastone of safety and comfort during autonomous driving of a host vehiclewithout the problems or drawbacks described above.

According to some embodiments, this is provided by a method forincreasing at least one of safety and comfort during autonomous drivingof a host vehicle, where the host vehicle comprises a vehicle systemcomprising;

an autonomous drive arrangement which comprises a plurality of sensorsarranged to monitor at least one of a vehicle surrounding and a vehiclecommunication system status,

a processing unit and a

control arrangement, arranged to control steering and velocity of thehost vehicle based on information received from the sensors

wherein the method comprises;

determining, by the processing unit, at least one of the estimatedprobability that at least one sensor will become unavailable and theestimated time or distance ahead until at least one sensor is determinedto become unavailable, the determination being based on a, by at leastone of the sensors, detected host vehicle or host vehicle surroundingcondition,

activating, by the autonomous drive arrangement, at least one firstcountermeasure based on at least one of the estimated probability, theestimated time and the estimated distance.

Since at least one first countermeasure is activated based on adetermined sensor unavailability, both safety and comfort during theautonomous driving of the host vehicle is achieved.

Thus, hereby is provided a method for increasing at least one of safetyand comfort during autonomous driving of a host vehicle, eliminating orat least reducing the problems and/or drawbacks associated with priorart methods.

Further features of, and advantages with, the embodiments herein willbecome apparent when studying the appended claims and the followingdetailed description. Those skilled in the art will realize thatdifferent features of the embodiments herein may be combined to createembodiments other than those described in the following, withoutdeparting from the scope of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of embodiments herein, including its particular featuresand advantages, will be readily understood from the following detaileddescription and the accompanying drawings, in which:

FIG. 1 a illustrates a vehicle having a vehicle system according to someembodiments herein.

FIG. 1 b illustrates a vehicle having a vehicle system according to someembodiments herein and surrounding vehicles on a road.

FIG. 2 a illustrates a vehicle having a vehicle system according to somefurther embodiments herein.

FIG. 2 b illustrates a vehicle having a vehicle system according to someembodiments herein driving from a point A to a point B on a road.

FIG. 3 illustrates a method according to embodiments herein.

DETAILED DESCRIPTION

As required, detailed embodiments are disclosed herein. However, it isto be understood that the disclosed embodiments are merely exemplary andembodiments may take various and alternative forms. The figures are notnecessarily to scale. Some features may be exaggerated or minimized toshow details of particular components. Therefore, specific structuraland functional details disclosed herein are not to be interpreted aslimiting, but merely as a representative basis for teaching one skilledin the art to variously employ the present disclosure.

Embodiments herein will now be described more fully with reference tothe accompanying drawings, in which example embodiments are shown.However, this application should not be construed as limited to theembodiments set forth herein. Disclosed features of example embodimentsmay be combined as readily understood by one of ordinary skill in theart to which this application belongs. Like numbers refer to likeelements throughout.

Well-known functions or constructions will not necessarily be describedin detail for brevity and/or clarity.

FIG. 1 a illustrates a host vehicle 1, arranged for autonomous driving.The host vehicle 1 may be any vehicle, such as a car, a bus or a truck,which is capable of driving autonomously on a road.

The host vehicle 1 comprises a vehicle system 2, which is arranged toincrease safety and/or comfort during autonomous driving of the hostvehicle 1. The vehicle system 2 comprises an autonomous drivearrangement 3 and a positioning system 4.

The autonomous drive arrangement 3 comprises a plurality of sensors 5,arranged to monitor a vehicle surrounding. The sensors 5 may be one ormore camera sensors 5 a, one or more radar sensors 5 b and/or one ormore lidar-sensors 5 c. As illustrated in FIG. 1 a, sensors 5 may bearranged at any position in/on the host vehicle 1 from where detectionof an interior or exterior condition is possible. Sensors 5 may forexample be arranged at a vehicle front-, side and/or rear portion, at avehicle grille, bumpers, rear-view-mirrors and/or a windshield. Somesensors 5 may be arranged in or near a vehicle compartment, chassis,motor, drivetrain and/or wheels. The sensor 5 position may depend on thetype of sensor. For example, a camera sensor 5 a and/or a lidar sensor 5c may be arranged at the inside of the windshield, while one or moreradar sensors 5 b may be arranged in the grille and/or bumpers.

A camera sensor 5 a may be e.g. a front- or rear facing digital cameraequipped with or connected to one or more processors with objectrecognition logics. Hereby surrounding objects, such as road lanes,other vehicles, traffic signs, pedestrians, animals, different obstaclesetc. may be detected and in some cases, identified/classified. Radarsensors 5 b may include transmitters that emit signals that bounces backfrom object around the host vehicle, and receivers that receive thereturned signals. The radar sensors 5 b may include e.g. ultra wide bandradars, narrow band radars and/or multi node radars. Lidar-sensors 5 cmay measure distances to objects by illuminating the objects with alaser and analyzing the reflected light. Other types of sensors 5 usedto monitor the vehicle surrounding may be e.g. ultrasonic sensors and/orinfrared sensors.

Some sensors 5 may be arranged to detect a vehicle communication systemstatus. Such sensors may determine signal strength/accessibility forsignals between a communication system in the host vehicle 1 andexternal communication arrangements. If a signal gets weaker, such thatthe communication decreases or fails, the sensors 5 may provide theautonomous drive arrangement 3 with information hereof. A communicationsystem status may decrease e.g. due to package loss and/or an decreasedsignal strength. The signals may relate e.g. to mobile or mobile-datasignals (such as GSM 3G, 4G, LTE, 5G) or any satellite and/or globalpositioning system signals (such as GPS, Galileo, GLONASS).

As illustrated in FIG. 1 a, the autonomous drive arrangement 3 comprisesat least one processing unit 6. According to some embodiments, theprocessing unit is connected to one or more memory units 7, configurableto store sensor data. In some embodiments the one or more processingunits 6 are used for processing in several different vehicle systems.Some processing units 6 may be dedicated to a specific processing task.In some embodiments the host vehicle 1 and/or the vehicle system 2 maycomprise a large number of processing units 6. The one or moreprocessing units 6 may be central processing units, CPUs, also referredto as central processor units, that carries out instructions of computerprograms/software, which, when executed perform basic arithmetical,logical, and input/output operations. The vehicle system 2 may alsocomprise an accelerated processing unit, APU, also referred to as anadvanced processing unit. An APU is a processing unit that includesadditional processing capability designed to accelerate one or moretypes of computations outside of the CPU. One or more processing units 6may comprise application programming interfaces, APIs, which specify howsoftware components may interact with each other.

In embodiments where the one or more processing units 6 comprise and/orare connected to one or more memory units 7, the one or more memoryunits 7 may be arranged in the host vehicle 1 and/or outside of the hostvehicle 1. In some embodiments, the one or more processing units 6 maysave information to the so called cloud, e.g. memory units 6 arranged inremote servers.

The autonomous drive arrangement 3 further comprises anelectrical/mechanical control arrangement 8, arranged to controlsteering and velocity of the host vehicle 1 based on informationreceived from the sensors 5. The control arrangement 8 is connected to avehicle steering system, such that the control arrangement 8, directlyor indirectly, may control a direction of at least some of the wheels ofthe host vehicle 1. Hereby e.g. a yaw rate of the host vehicle 1 may beadjusted, such that the driving direction of the host vehicle 1 isadjusted in accordance with the input from the control arrangement 8.The control arrangement 8 is also connected to a vehicle engine and avehicle braking system, such that the control arrangement 8, directly orindirectly, may control acceleration and/or deceleration of the hostvehicle 1. The control arrangement 8 may e.g. increase a vehiclevelocity by increasing the engine speed, and decrease the vehiclevelocity by motor-braking or by activation of one or more wheel brakes.The control arrangement 8 may e.g. be connected to an ABS (anti-lockbraking system), such that one or more wheel brakes may be activatedselectively.

According to some embodiments, the vehicle system 2 further comprises apositioning system 4, arranged to determine a host vehicle position anddriving direction/heading. The positioning system 4 may determine thehost vehicle position and driving direction e.g. via a satellite basedglobal positioning system and/or matching relatively a map. A compassmay be used for determination of a vehicle direction. The positioningsystem 4 may comprise or be connected to a navigation system.

The processing unit 6 is arranged to determine an estimated probabilitythat at least one sensor 5 will become unavailable and/or an estimatedtime to or distance ahead until at least one sensor 5 is determined tobecome unavailable. The probability that at least one of the sensors 5will become unavailable within a certain time amount or within a certaindistance ahead of the host vehicle 1 is based on a host vehicle 1 orhost vehicle surrounding condition, detected by one or more sensors 5.The vehicle system 2 is further arranged to activate, by the autonomousdrive arrangement, at least one first countermeasure, based on theestimated probability and/or the estimated time and/or the estimateddistance.

According to some embodiments, the processing unit 6 is arranged todetermine a duration of time, for which the at least one sensor 5 isunavailable. The duration of time may depend e.g. on host vehiclesurrounding conditions, host vehicle velocity, traffic intensity.According to some embodiments, the threshold duration of time may be oneor a few seconds, such as 1-15 s. According to some embodiments, thethreshold duration of time may be about 3 s.

FIG. 1 b illustrates the host vehicle 1 and the vehicle system 2 as seenfrom above. During autonomous driving, the sensors arranged in/on thehost vehicle 1 are arranged to continuously monitor the host vehiclesurrounding along a road 10, on which the host vehicle 1 is travelling.The sensors thus gather the type of information that a vehicle operatornormally perceives through his/her senses during manual or semi-manualdriving. The information may relate to any factor which may affect acurrent or upcoming traffic situation. The detected information may e.g.relate to road direction, road surface, road friction, road lanes,surrounding climate and weather conditions, light conditions, othervehicles, objects, pedestrian, bicyclists, animals etc. on or in thevicinity of the road, nearby buildings or obstacles, traffic intensity,general traffic information, upcoming crossings etc.

The information detected via the sensors is used as input to the hostvehicle control arrangement. The control arrangement may be configuredto control the steering and velocity of the host vehicle 1 in a mannerthat an attentive and experienced driver would have done in a similarsituation, i.e. to follow a traffic rhythm and avoid potentiallydangerous situations. For example, if sensors detect that a distance 15a to a slower driving vehicle 12 ahead of the host vehicle 1 decreasesbelow a predefined safety distance, or with a closing velocity above athreshold velocity, the vehicle system 2 may be configured to apply thebrakes of the host vehicle 1. If a distance 15 b, 15 c to surroundingvehicles 12 becomes too small, the host vehicle 1 may adjust its lateralposition, such that the distance 15 b, 15 c is increased. The vehiclesystem 2 may be configured to increase the safety margins to othervehicles more in higher speeds, and may adjust brake forces and yawrates e.g. in accordance with detected ice or other slippery surfaces onthe road 10.

The vehicle system 2 is dependent on robust sensor information in orderto provide autonomous driving functionality. If one or more sensorsbecomes defect, blocked or in any other way unavailable to detect thehost vehicle surroundings and/or a vehicle communication system status,the host vehicle operator may have to take control over the vehicleuntil the sensor or sensors functions properly again. In order to avoidthat the vehicle operator will have to take control of the host vehicle1, if one or more sensors become unavailable, the processing unit isarranged to determine the estimated probability that at least one sensorwill become unavailable and/or the estimated time or distance aheaduntil at least one sensor is determined to become unavailable. Theprobability that at least one of the sensors will become unavailable,within a certain amount of time or within a certain distance ahead ofthe host vehicle 1, is based on a detected host vehicle or host vehiclesurrounding condition, detected by one or more sensors. The vehiclesystem 2 is further arranged to activate at least one firstcountermeasure, based on the estimated probability and/or the estimatedtime and/or the estimated distance.

In FIG. 2 a the host vehicle 1 is illustrated in a road environment. Thehost vehicle 1 is depicted when driving on a road 10 provided with roadmarkings 11. Ahead of the host vehicle 10 a surrounding vehicle 12 isillustrated.

The host vehicle 1 comprises the vehicle system 2, which allows the hostvehicle 1 to drive autonomously. The host vehicle 1 may therefore bereferred to as an autonomous vehicle, in which many or all of vehicleoperator tasks, such as steering, accelerating and braking are performedautomatically by the vehicle system 2. The vehicle operator may insteadfocus on secondary tasks, such as reading, socializing or browsing theinternet, instead of the otherwise primary task of driving the vehicle.The vehicle system 2 may be connected to and/or comprise a number ofco-operating subsystems, such as adaptive cruise control systems, lanedeparture control systems, collision avoidance system, traffic signrecognition systems, communication systems, navigation systems,ultrasonic sensor systems, infrared camera systems, inertial measuringsystems, intelligent transportation systems, safe road train systems,automatic parking systems etc.

According to some embodiments, the activation of at least onecountermeasure is based on a, by at least one of the sensors 5, detectedhost vehicle surrounding condition in form of sun-light, negativelyaffecting a vehicle camera sensor 5 a. This scenario is depicted in FIG.2 a. When the host vehicle 1 autonomously drives in a direction where alongitudinal direction of the host vehicle 1, or a monitoring fielddirection 5 d of the camera sensor 5 a, is larger than a predeterminedangle relative to the sun 13, the camera sensor 5 a is determined to beavailable. When the host vehicle 1 continues along the road 10 in FIG. 2a, the angle relative to the sun 13 will decrease. When the longitudinaldirection of the host vehicle 1 or the monitoring field direction 5 d ofthe camera sensor 5 a is equal or less than the predetermined angle tothe sun 13, the risk that the sun 13 shines straight into the lens ofthe camera sensor 5 a is high. The lens may become saturated, wherebythe sensor 5 a may fail to provide sensor information on the hostvehicle surrounding to the control arrangement 8. If the sensor 5 afails to provide sensor information on the host vehicle surrounding tothe control arrangement 8, the sensor 5 is determined to be unavailable.The vehicle system 2 may use information on an upcoming road direction,a selected route and/or historical data for the determination of thetime and/or distance until the sensor is determined to becomeunavailable.

Since expected upcoming sensor unavailability is determined before thesensor 5 actually becomes unavailable, one or more countermeasures tothe determined sensor unavailability may be activated. In the FIG. 2a-illustration, where the host vehicle driving direction approaches thesun 13, such a determination may be based on factors such as theluminous intensity of the sun 13 and the vertical and/or horizontaldistance between the host vehicle driving direction and the position ofthe sun. The relationship may be expressed e.g. as a mathematicalformula. Upcoming curves and crests, clouds, houses trees, particles inthe atmosphere etc. may be taken into account for the determination. Thedetermination may also be based on the present time of the day, thegeographical position of the host vehicle etc. For example, a sensor maybe determined to be unavailable if a probability that the sensor willstop to function properly is higher than a pre-defined probability,According to some embodiments such probability may be between 50-99%,such as 60%, 70%, 80% or 90%.

According to some embodiments, the determination of whether a sensorwill be unavailable or not is based entirely on sensor data. Thedetermination may then be performed without any previously savedinformation.

The vehicle system 2 may be arranged to activate, by the autonomousdrive arrangement 3, at least one first countermeasure if the estimatedprobability that at least one sensor will become unavailable exceeds athreshold probability or if the estimated time or distance ahead, untilat least one sensor is determined to become unavailable, is below athreshold level. Different threshold levels may be selected, e.g.depending on which level of safety that is required, and if informationfrom available sensors may compensate for the determined sensorunavailability.

As mentioned above, several types of sensors 5 may be used to monitorthe host vehicle surroundings. According to some embodiments, theactivation of at least one countermeasure may be based on a, by at leastone of the sensors, detected host vehicle surrounding condition in formof a weather condition, negatively affecting at least one of a camerasensor, a radar sensor and a lidar sensor.

In some situations, a sensor 5 may be unavailable due to obstacles nearthe road 10. In FIG. 2 a the vehicle system 2 may determine that e.g. acamera sensor 5 a will be at least temporarily unavailable if e.g. abuilding 14 blocks a part of or the entire monitoring field 5 d. Asensor 5 may also be determined to be unavailable due to a curve or acrest. A radar sensor 5 b may not be able to detect relevant areas ofthe host vehicle surrounding if its field of view is blocked byobstacles. Radar sensors 5 b may also be blocked e.g. due to rain, snowand water spray from surrounding vehicles. During certain temperatureand/or humidity conditions, moisture on the inside of the windshield maybe predicted in advance, e.g. from communicated weather forecasts. Asensor may be determined to be unavailable during such conditions.

In FIG. 2 b the host vehicle 1 is illustrated on a road in a roadnetwork 10 a, 10 b. In this illustrated embodiment the host vehicle 1 isabout to autonomously drive from point A to point B. According to someembodiments the vehicle system 2 comprises a communication systemarranged for communication between the host vehicle 1 and externalcommunication arrangements. The host vehicle 1 may then be arranged toreceive data relating to host vehicle surrounding conditions from theexternal communication arrangements. According to some embodiments, thevehicle system 2 further comprises a navigation system arranged toprovide the autonomous drive arrangement with information on theavailable routes 10 a, 10 b of the road network surrounding the hostvehicle 1 and to allow a vehicle operator to input a preferred route.The navigation system may be connected to the abovementioned positioningsystem 4.

Examples of host vehicle surrounding conditions which may negativelyaffect a sensor 5 are given in the following. Diffuse lane markers 16may negatively affect a camera sensor. A tunnel 17 may negatively affecta GPS-signal-sensor. The sun 13 may negatively affect a camera sensor.In a predefined or delimited geographical area 18 a communicationcapacity may be insufficient, which may negatively affect a signalbetween the host vehicle 1 and external communication arrangements, suchas servers, roadside units, surrounding vehicles and/or intelligenttraffic systems.

Thus, according to some embodiments, the activation of at least onecountermeasure may be based on host vehicle surrounding conditioninformation, indicative of a communication capacity in the predefinedgeographical area 18. Hence, a countermeasure may be activated e.g. if adata signal or positioning signal becomes weaker. This may be the casee.g. if the host vehicle 1 is far from a telecommunication-mast, or if asignal is blocked e.g. by the illustrated mountain 19.

As mentioned above, one or more countermeasures may be activated when asensor 5 is determined to become unavailable. For example, two, three,four or five different countermeasures may be activated. The one or morecountermeasures may include: activation of a host vehicle operatoralert, indicative of an upcoming reduced autonomous driving capacity,disablement of one or more autonomous drive functions.

A countermeasure may also be: an increase safety distance between thehost vehicle 1 and at least one object in the host vehicle surrounding,a change of vehicle velocity, stopping the vehicle or initiating alateral displacement. A countermeasure may also be dead reckoning. Deadreckoning is a process for estimating a value (e.g. indicative of avelocity and/or a position) based on earlier values, together withoccurring changes. If a sensor becomes unavailable, dead reckoning maybe used to continue to control the vehicle along a path determined whensensors were available. Hence, historically gathered data may be usedfor shorter periods of time until sensor information is available again.

FIG. 3 illustrates a method 100 for increasing at least one of safetyand comfort during autonomous driving of a host vehicle, where the hostvehicle comprises a vehicle system with: an autonomous drivearrangement, the autonomous drive arrangement comprising a plurality ofsensors arranged to monitor at least one of a vehicle surrounding and avehicle communication system status, a processing unit, a controlarrangement, arranged to control steering and velocity of the hostvehicle based on information received from the sensors.

The method 100 comprises the step of determining 101, by the processingunit, at least one of the estimated probability that at least one sensorwill become unavailable and the estimated time or distance ahead untilat least one sensor is determined to become unavailable. Thedetermination is based on a, by at least one of the sensors, detectedhost vehicle or host vehicle surrounding condition. The method 100further comprises the step of activating 102, by the autonomous drivearrangement, at least one first countermeasure based on at least one ofthe estimated probability, the estimated time and the estimateddistance.

If the determination of sensor unavailability is based on a, by at leastone of the sensors, detected host vehicle surrounding condition, thetime/distance may be small. For example, if water splash from asurrounding vehicle is detected, the time until the sensor is determinedto be unavailable may be e.g. a few milliseconds or a few seconds. If asunset ahead is detected, the time until the sensor is determined to beunavailable may be e.g. a few seconds or a few minutes.

Although aspects have been described with reference to exampleembodiments, many different alterations, modifications and the like willbecome apparent for those skilled in the art. Therefore, it is to beunderstood that the foregoing is illustrative of various exampleembodiments and the scope of the appended claims is not to be limited tothe specific embodiments disclosed and that modifications to thedisclosed embodiments, combinations of features of disclosed embodimentsas well as other embodiments are intended to be included within thescope of the appended claims.

As used herein, the term “comprising” or “comprises” is open-ended, andincludes one or more stated features, elements, steps, components orfunctions but does not preclude the presence or addition of one or moreother features, elements, steps, components, functions or groupsthereof.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the disclosure. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the disclosure.Additionally, the features of various implementing embodiments may becombined to form further embodiments.

What is claimed is:
 1. A vehicle system configured to increase at leastone of safety and comfort during autonomous driving of a host vehicle,the vehicle system comprising: an autonomous drive arrangementcomprising a plurality of sensors configured to monitor at least one ofa vehicle surrounding and a vehicle communication system status, aprocessing unit, and a control arrangement configured to controlsteering and velocity of the host vehicle based on information receivedfrom the sensors; wherein the vehicle system is configured to determine,by the processing unit, at least one of an estimated probability that atleast one sensor will become unavailable, and an estimated time ordistance ahead until at least one sensor is determined to becomeunavailable, the determination being based on a detected host vehiclecondition or a detected host vehicle surrounding condition, by at leastone of the plurality of sensors; wherein the vehicle system further isconfigured to activate, by the autonomous drive arrangement, at leastone first countermeasure based on at least one of the estimatedprobability, the estimated time and the estimated distance.
 2. Thevehicle system according to claim 1 wherein a sensor is determined to beunavailable if a sensor performance level is below a threshold sensorperformance level, and in that at least one first countermeasure isactivated only if the sensor is determined to be unavailable for aduration of time that exceeds a threshold duration of time.
 3. Thevehicle system according to claim 1 wherein the autonomous drivearrangement is configured to activate at least one second countermeasurebased on at least one of the estimated probability, the estimated timeand the estimated distance.
 4. The vehicle system according to claim 1wherein the activation of at least one countermeasure is based on adetected host vehicle surrounding condition, detected by at least one ofthe plurality of sensors, in a form of sun-light negatively affecting avehicle camera sensor.
 5. The vehicle system according to claim 1wherein the vehicle system is configured to activate, by the autonomousdrive arrangement, at least one first countermeasure if the estimatedprobability that at least one sensor will become unavailable exceeds athreshold probability or if the estimated time or distance ahead untilat least one sensor is determined to become unavailable is below athreshold level.
 6. The vehicle system according to claim 1 wherein theactivation of at least one countermeasure is based on a detected hostvehicle surrounding condition, detected by at least one of the pluralityof sensors, in a form of a weather condition negatively affecting atleast one of a camera sensor, a radar sensor and a lidar sensor.
 7. Thevehicle system according to claim 1 further comprising a communicationsystem configured for communication between the host vehicle andexternal communication arrangements, wherein the host vehicle isconfigured to receive data relating to host vehicle surroundingconditions from the external communication arrangements.
 8. The vehiclesystem according to claim 7 wherein the activation of at least onecountermeasure is based on a detected decreased communication capacity,detected by at least one of the plurality of sensors, between the hostvehicle and at least one external communication arrangement.
 9. Thevehicle system according to claim 7 wherein the activation of at leastone countermeasure is based on a host vehicle surrounding conditioninformation indicative of a communication capacity in a predefinedgeographical area.
 10. The vehicle system according to claim 1 whereinthe vehicle system is configured to activate one or morecountermeasures, selected from a host vehicle operator alert indicativeof an upcoming reduced autonomous driving capacity, a disablement of oneor more autonomous drive functions, an increase of safety distance to atleast one object in the vehicle surrounding, a change of vehiclevelocity, a stop of the host vehicle, activation of dead reckoning. 11.A vehicle comprising a vehicle system according to any one of claim 1.12. A method for increasing at least one of safety and comfort duringautonomous driving of a host vehicle including a vehicle system, thevehicle system comprising an autonomous drive arrangement comprising aplurality of sensors configured to monitor at least one of a vehiclesurrounding and a vehicle communication system status, a processingunit, and a control arrangement configured to control steering andvelocity of the host vehicle based on information received from thesensors, the method comprising: determining, by the processing unit, atleast one of the estimated probability that at least one sensor willbecome unavailable and the estimated time or distance ahead until atleast one sensor is determined to become unavailable, the determinationbeing based on a detected host vehicle condition or a detected hostvehicle surrounding condition, detected by at least one of the pluralityof sensors; activating, by the autonomous drive arrangement, at leastone first countermeasure based on at least one of the estimatedprobability, the estimated time and the estimated distance.